An official website of the United States government
Summary Stress often induces plant trait plasticity, and microbial communities also alter plant traits. Therefore, it is unclear how much plasticity results from direct plant responses to stress vs indirect responses due to stress‐induced changes in soil microbial communities.To test how microbes and microbial community responses to stress affect the ecology and potentially the evolution of plant plasticity, I grew plants in four stress environments (salt, herbicide, herbivory, and no stress) with microbes that had responded to these same environments or with sterile inoculant.Plants delayed flowering under stress only when inoculated with live microbial communities, and this plasticity was maladaptive. However, microbial communities responded to stress in ways that accelerated flowering across all environments. Microbes also affected the expression of genetic variation for plant flowering time and specific leaf area, as well as genetic variation for plasticity of both traits, and disrupted a positive genetic correlation for plasticity in response to herbicide and herbivory stress, suggesting that microbes may affect the pace of plant evolution.Together, these results highlight an important role for soil microbes in plant plastic responses to stress and suggest that microbes may alter the evolution of plant plasticity.
more »
« less
Herbicides as anthropogenic drivers of eco‐evo feedbacks in plant communities at the agro‐ecological interface
Herbicides act as human-mediated novel selective agents and community disruptors, yet their full effects on eco-evolutionary dynamics in natural communities has only begun to be appreciated. Here we synthesize how herbicide exposures can result in dramatic phenotypic and compositional shifts within communities at the agro-ecological interface and how these in turn affect species interactions and drive plant (and plant-associates’) evolution in ways that can feedback to continue to affect the ecology and ecosystem functions of these assemblages. We advocate a holistic approach to understanding these dynamics that includes plastic changes and plant community transformations and also extends beyond this single trophic level targeted by herbicides to the effects on non-target plant-associated organisms and their potential to evolve, thereby embracing the complexity of these real-world systems. We make explicit recommendations for future research to achieve this goal and specifically address impacts of ecology on evolution, evolution on ecology, and their feedbacks so that we can gain a more predictive view of the fates of herbicide-impacted communities.
more »
« less
- PAR ID:
- 10164216
- Date Published:
- Journal Name:
- Molecular Ecology
- ISSN:
- 0962-1083
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Background and Aims When plant communities are exposed to herbicide ‘drift’, wherein particles containing the active ingredient travel off-target, interspecific variation in resistance or tolerance may scale up to affect community dynamics. In turn, these alterations could threaten the diversity and stability of agro-ecosystems. We investigated the effects of herbicide drift on the growth and reproduction of 25 wild plant species to make predictions about the consequences of drift exposure on plant-plant interactions and the broader ecological community. Methods We exposed potted plants from species that commonly occur in agricultural areas to a drift-level dose of the widely used herbicide dicamba or a control solution in the glasshouse. We evaluated species-level variation in resistance and tolerance for vegetative and floral traits. We assessed community-level impacts of drift by comparing species evenness and flowering networks of glasshouse synthetic communities comprised of drift-exposed and control plants. Key Results Species varied significantly in resistance and tolerance to dicamba drift: some were negatively impacted while others showed overcompensatory responses. Species also differed in the way they deployed flowers over time following drift exposure. While drift had negligeable effects on community evenness based on vegetative biomass, it caused salient differences in the structure of coflowering networks within communities. Drift reduced the degree and intensity of flowering overlap among species, altered the composition of groups of species that were more likely to coflower with each other than with others, and shifted species roles (e.g., from dominant to inferior floral producers and vice versa). Conclusions These results demonstrate that even low levels of herbicide exposure can significantly alter plant growth and reproduction, particularly flowering phenology. If field-grown plants respond similarly, then these changes would likely impact plant-plant competitive dynamics and potentially plant-pollinator interactions occurring within plant communities at the agro-ecological interface.more » « less
-
Summary Microbial communities can rapidly respond to stress, meaning plants may encounter altered soil microbial communities in stressful environments. These altered microbial communities may then affect natural selection on plants. Because stress can cause lasting changes to microbial communities, microbes may also cause legacy effects on plant selection that persist even after the stress ceases.To explore how microbial responses to stress and persistent microbial legacy effects of stress affect natural selection, we grewChamaecrista fasciculataplants in stressful (salt, herbicide, or herbivory) or nonstressful conditions with microbes that had experienced each of these environments in the previous generation.Microbial community responses to stress generally counteracted the effects of stress itself on plant selection, thereby weakening the strength of stress as a selective agent. Microbial legacy effects of stress altered plant selection in nonstressful environments, suggesting that stress‐induced changes to microbes may continue to affect selection after stress is lifted.These results suggest that soil microbes may play a cryptic role in plant adaptation to stress, potentially reducing the strength of stress as a selective agent and altering the evolutionary trajectory of plant populations.more » « less
-
The effects of animal homeostatic function on ecological interactions have not been well-integrated into community ecology. Animals mediate environmental change and stressors through homeostatic shifts in physiology and behavior, which likely shape ecological interactions and plant communities. Animal responses to stressors can alter their habitat use, selective foraging, and stoichiometry, which can in turn affect trophic interactions, plant growth, reproduction, and dispersal. Here, we describe a community physiological ecology framework that integrates classical ecological theory and emerging empirical approaches to test how animal homeostatic responses to environmental change mediate ecological interactions and shape communities. Interdisciplinary approaches could provide essential data to characterize and forecast community responses to rapid global environmental change.more » « less
-
The finding that adaptive evolution can often be substantial enough to alter ecological dynamics challenges traditional views of community ecology that ignore evolution. Here, we propose that evolution might commonly alter both local and regional processes of community assembly. We show how adaptation can substantially affect community assembly and that these effects depend on regional (metacommunity) factors, including environmental heterogeneity and its spatial structure. In particular, early colonists can often arrive from a nearby community, adapt to local conditions, and subsequently alter the establishment or abundance of late-arriving species, often producing an evolutionary priority effect. We also discuss how interaction type and relative rates of colonization, evolution, and community interactions determine divergent community outcomes. We describe new conceptual approaches that provide insights into these dynamics and statistical methods that can better evaluate their importance. Overall, we demonstrate that accounting for adaptation during community assembly opens up novel ways for making progress on fundamental questions in community ecology.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1111/mec.15510
